Be wary of those estimates, as he continues the statistically dubious habit of normalizing mass to 78kg. Thus his reported numbers are always going to be significantly wrong, by definition. This tends to be ignored by those trying to use the data to make a point.

He also continues to ignore the race situation/drafting effects, pretending they do not exist.

He mentions Armstrong is putting out power numbers vintage 1994-95 on the climbs. I always wondered about Armstrong's state of mind after the 95 tour. He was humiliated during the Liege stage when he could not hold the Hogs wheel, who just just got on to Indurain's wheel who had attacked the LA-Hog group from behind. IIRC, I think he passed by Indurain in the ITT the next day.

dbrower wrote:Be wary of those estimates, as he continues the statistically dubious habit of normalizing mass to 78kg. Thus his reported numbers are always going to be significantly wrong, by definition. This tends to be ignored by those trying to use the data to make a point.

He also continues to ignore the race situation/drafting effects, pretending they do not exist.

-dB

There is nothing wrong with his method, it is totally justified as you could easily check out for yourself by running examples on analyticcycling.com if you don't want to do the calculation by yourself.

Granted that in the case of Rujano or of Backstedt you might have to make a small but not totally negligible correction but not for the huge majority of racers, those between 60 and 80 kg.

It is also unfair to Frédéric Portoleau to say that he does not take into account race situations . For example, in the case of his Verbier calculation he made a detailed addendum taking care of the wind and comparing his calculations with the measurements obtained by one the racers equipped with an SRM.
He also goes on location and runs comparaisons with the data he collects with his own Powertap ( or SRM)

As you can see in the case of the Morzine-Avoriaz climb he goes to a lot of trouble to actually find out that the courses followed by the racers were not absolutely identical in 79, 94, 2010, etc.

Glad someone pointed this out. Yes its "relatively low", and I wonder whether we'll see any drastic changes come the Pyrenees. What is looking to be certain is that this is much cleaner peloton than the Armstrong era, thats why its "relatively low". Ross Tucker of Science of Sport had it that a max of 6.2 is strongly indicative of a suspicious performance, not impossible.

Someone emailed me today saying that he viewed SRM files from the hilly stages and Contador and Schleck were both doing roundabout 5.6 W/kg (Madeline). The funny thing was that in that stage, Armstrong was dropped. Go back to what Ferrari used to say - that to win, 6.7 W/kg was the magic number and that Lance could produce this easily. Where was it I read, that The Kid Carmichael, in an interview, even pushed that number unscrupulously to 7 W/kg. Question is how can his p/wt drop so drastically now? This will be a good topic for discussion.

Schleck and Contador were clearly riding tactically against each other rather than concentrating on climbing as fast as possible. Question - how much harder could those two riders have taken that climb?

For me it is a perfect example of the pointlessness of looking at VAM in a race situation to try and compare an effort against another one. Unless you have 2 riders doing ITTs up the climb then you are almost guaranteed to have tactical factors that can't easily be quantified (because you can't see what the rider is thinking).

Martin318is wrote:Whats the point of looking at data from this year's AX-3?

Schleck and Contador were clearly riding tactically against each other rather than concentrating on climbing as fast as possible. Question - how much harder could those two riders have taken that climb?

For me it is a perfect example of the pointlessness of looking at VAM in a race situation to try and compare an effort against another one. Unless you have 2 riders doing ITTs up the climb then you are almost guaranteed to have tactical factors that can't easily be quantified (because you can't see what the rider is thinking).

+1

Using inferential power numbers to make inferences about PEDS seems way to vague to be fair to anyone.

Interesting discussion. And seeing how I threw out that 6.2W/kg figure, I've also been interested in tracking the stats.

Unfortunately, we never see the real numbers from the top men, but we can get a lot of data off the SRM website (http://www.srm.de/). So here are some "facts":

1. Chris Horner:

On the short climb (3km) up to Mende the other, Horner finished 31 seconds behind Contador, having begun the climb with him. Horner's average power output for 10 minutes of climbing was 6.6 W/kg (422W). Nothing wrong with that, it's a really short effort.

For context, consider Horner on Ax-3-Domaines the other day. That climb took him just under 24 minutes, and his power output was 5.8 W/kg (370W). He conceded about 90 seconds to Schleck and Contador and co.

Then even longer was the climb of the Port de Pailheres, which took 48:37, and that was done at 5.4W/kg (344W). Of course, it's not a finishing climb, so the hammer isn't down, but it does reflect what the peloton is doing.

Edit: Also, Horner's data from the Port de Bales are interesting. He finished this day with Basso, conceding approx. 3 minutes to Contador's group by the finish (not 100% sure of the gap at the summit, but imagine it would be 3 min ± 20 seconds). This climb took 49:30, and was done at an average of 342W/kg (5.2W/kg - about the same as the Port de Pailheres of similar duration).

And then very interesting, we also have the data of Chris Anke Sorensen, who has been the last man to peel off for Andy Schleck. And on the Port de Bales, he rode at the front of the peloton for 21:34 and produced 6.1W/kg. The smaller Schleck, riding behind him, would produce less than this - perhaps 5.8W to 6.0W/kg, and that's a good indication of the power produced by those top contenders.

How much are those 90 seconds worth? Using the SRM to 'validate' your calculations, it might be interesting to calculate. Will have a look later, just have to sort out some things first. Cozy Beehive will beat me to it and probably do a better job than I can...

But I think the Tour is substantially slower. The days where climbs lasting 40 minutes or more were done at even just above 6W/kg WITH attacks are no longer with us...and never mind the 6.7W/kg that we've heard of, and know that guys were producing for close to 40 minutes.

On the note of Portoleau, I do feel that all he needs to do is give the times. He has this massive database and if you could show that they did Ax-3-Domaines 90 seconds slower than in previous years, that's compelling. Even with temperature and race situation, you'd have a tough time explaining that difference away entirely. And then the other thing to do is take the average time of the top 20, and positions say 50 to 60, to get an idea of depth. Almost certain it's a lot slower.

The other thing about the power, as Martin points out, is that in theory, if they rode one pace, they'd be faster. But I don't remember one paced riding too often. There are always attacks. Schleck-Contador was extreme the other day, but that's why it would be most interesting to look at the depth and quality.

You can see it in the racing, because as fierce as the attacks are, they're not doing the same damage as previous years, they're less frequent and interspersed with much slower riding, and the guy in the breakaway (Voeckler and Riblon) have held off.

Then, you'll see a big graphic for the srm blog. Click on that. Lots of power data straight from the riders with excellent in-stage power comparisons.

I see the process of normalizing the data as represented in the other link given as fraught with error. I don't find the data terribly useful because the normalizing process is takes the wrong kind of complexity out of the data.